Marshall Municipal Utilities

Grit Removal and Preaeration Building

The grit removal and preaeration building houses three Hoffman blowers, related electrical equipment and piping that are capable of pumping 600 cubic feet per minute (cfm) of air into the waste stream and #1 sludge holding basin. This coarse bubble diffused air revitalizes the wastewater by reintroducing dissolved oxygen (DO) into the waste stream.

The basin is also designed to allow grit (heavy organic material) to settle while keeping the light organic material in suspension. The grit is removed mechanically via chain and bucket assemblies and conveyor belt. The removed grit is blended with sludge and land applied.

Once the grit is removed, the wastewater flows to the primary clarifiers for further treatment.